1. Field of the Invention
The present invention relates to a system for preventing burn-in of the screen of a display apparatus in a system for presenting mixed reality or virtual reality.
2. Description of the Related Art
In recent years, active researches have been performed on mixed reality (MR) aiming at seamless coupling of the real and the virtual spaces. An image display apparatus for presenting mixed reality has, for example, the following configuration. Specifically, the image display apparatus superimposes, onto real space images captured by an imaging apparatus such as a video camera, virtual reality space images (for example, virtual objects, text information drawn by using computer graphics) generated according to the position and orientation of the imaging apparatus. For example, a head-mounted display (HMD) can be used for such an image display apparatus.
The image display apparatus is implemented also by the optical see-through method for displaying, on an optical see-through type display mounted on a user's head, a virtual space image generated according to the position and orientation of the user's viewpoint.
Meanwhile, Japanese Patent Application No. 2007-281654 also discusses a method for preventing burn-in when displaying an image on a display. Specifically, in the method, an audio-video (AV) apparatus outputs video data to a display apparatus configured to display a video image on a display screen, and a control apparatus capable of performing data communication mutually with the AV apparatus detects that the video data output from the AV apparatus is in a still image state. In a case where the control apparatus detects that the video data is in the still image state, the control apparatus stops reproducing the video data, and changes the state of a power source unit of the AV apparatus from an ON state to an OFF state by executing a power source changeover program, thereby preventing burn-in.
Japanese Patent Application No. 2002-251667 discusses a method for detecting by using a sensor whether a user wears an HMD, and if the user does not wear the HMD, turning OFF the power of the HMD to effectively prevent unnecessary power consumption when the HMD is not in use.
However, with the method discussed in Japanese Patent Application No. 2007-281654, since the control apparatus detects that the video data is in the still image state and controls the power source, there may be a case where the control apparatus stops the video data or turns OFF the power of the display while the user is experiencing mixed reality via the HMD. This case causes a problem that the mixed reality video image is suddenly interrupted to make the user unable to continue experiencing it, which disturbs the user's immersive feeling.
The method discussed in Japanese Patent Application No. 2002-251667 has a problem that it cannot be easily performed because it involves the cost for adding a hardware configuration.